Study on Systemizing the Technology on the Investigation and Analysis of Deep Underground Geological Environment, 2003

Kojima, Keiji*; Onishi, Yuzo*; Watanabe, Kunio*; Nishigaki, Makoto*; Tosaka, Hiroyuki*; Shimada, Jun*; Aoki, Kenji*

The following was done in this year with the aim of systemizing the technology on the investigation and analysis to grasp deep underground geological environment in relation to the radioactive waste disposal. (1) The study to extract the research and development (R&D) subjects turned to the practical investigation and analysis of deep underground geological environment. (2) The study on the advanced technical basis of the investigation and analysis of deep underground geological environment. It continued in the former year and got the following results. Concerning (1), the concrete investigation, measurement and numerical / chemical analysis were enforced about the following item and extracted some subjects with the viewpoint of radioactive waste disposal. 1: The subjects extracted with the viewpoint of the repository design and engineering technology. *The evaluation technique of the excavation disturbed zone (EDZ) by acoustic emission (AE) or micro seismicity measurement. *Fracture sealing technique such as vibration grouting toward low permeable rock mass. 2: The subject extracted with the viewpoint of the safety assessment. *Precipitation of the metal hydroxide (non-crystallized) through migration process in rock mass and change to the crystallized oxide.3: The subjects extracted with the viewpoint of the geological environment. *Fracture distribution characteristics around the fault, it can think to meet in the underground facilities and the prediction of long term activities of the fault. *Natural sealing process by the secondary filling materials (iron oxide and carbonate etc.) in the fracture of rock mass and that influence which may be given to the long-term migration and release of nuclides. The advanced research subjects among the each field of 1, 2, 3 were also discussed. Concerning (2), the evaluation of the results and a way to the practical use were discussed on the R&D activities of the following item.